I. Field of the Invention
The present invention relates to communication. More particularly, the present invention relates to a novel and improved method of invoking and canceling a voice or a data connection.
II. Description of the Related Art
A variety of apparatus exists today that use standard telephone networks to convey data from one terminal to another. One of the most common terminals which uses a standard telephone network to convey data is the facsimile (FAX) machine. Like other terminal equipment that uses standard telephone networks, a FAX machine uses a modem to translate digital information to audible analog tones for transmission over the telephone network. At the receiving FAX machine, a modem is used to convert the tones back into an estimate of the original digital information sent by the transmitting FAX machine.
With the deployment of cellular and personal communications wireless systems, the end user may wish to connect his terminal equipment to a mobile communication device instead of directly to a land telephone network. Digital wireless communication equipment typically uses vocoders to convert incoming voice signals into digital bits for transmission over the channel and to perform the reverse function. Vocoders are tailored to sample and compress human voice. Because modem tones differ significantly from human voice, the vocoder can degrade the modem tones. Also maximizing the capacity of a wireless system in terms of the number of simultaneous users that can be handled is extremely important. Digitizing modem tones with a vocoder and sending them over the digital wireless link is an inefficient use of the radio channel.
A more efficient, flexible, and reliable transmission means is to provide a mechanism to transmit the digital data over the digital wireless link directly, thus providing a mobile unit that has the capability to receive and produce both audible voice and digital data. This configuration presents some unique opportunities to take advantage of the digital link to provide high quality service. One principal advantage is that a mobile unit capable of both data and voice services may be used simultaneously to provide both services.
It is therefore the object of the present invention to provide a method and apparatus of invoking simultaneous voice and data service with a single mobile unit.